Electronic devices may, at times, be used in circumstances in which the microphone is subject to transient or sustained airflow or air pressure disturbances, such as “popping” pressure changes or wind noise. In certain conditions, airflow or pressure changes incident upon the microphone may be so substantial as to be picked up by the microphone and produce an undesirable noise signal that interferes with the microphone's use and provides an unpleasant and distracting noise to the user. During a phone call, for example, audible airflow noise may make sound transmissions difficult to hear on the part of a listener.
Typically, several types of omni-directional microphones have been used in portable electronic devices. Although omni-directional microphones are considered to be less sensitive to wind-noise from air blowing into the microphone as compared to directional microphones, wind-noise or scratching due to coverage of the microphone port often remains problematic. Noise-cancelling algorithms may be used to combat the problem and improve acoustical performance; however, such electronic solutions require power consumption and are not always suitable in electronic devices having limited battery capacity, such as cell phones and tablets.
Furthermore, conventional microphone port designs can include small openings that may be easily covered up by a hand or finger of the user. Covering the microphone port may trap air at the microphone port opening. This trapped air within the microphone port can lead to air vibrations within the port that result in loud scratching noises that are undesirable to the user and may result in low-quality microphone recordings or transmissions.